The Symbolics Space Cadet keyboard had dedicated paren keys:

http://xahlee.info/kbd/space-cadet_keyboard.html

Here's the rumor I heard from Gumby about why it was designed that way:

https://news.ycombinator.com/item?id=12187422

DonHopkins on July 29, 2016 | parent | context | favorite | on: Unexecute

The Lisp Machine keyboard had dedicated open and close parenthesis keys, so you could hold a hefty bag of nitrous oxide in your other hand while you typed s-expressions.

qwertyuiop924 on July 29, 2016 [–]

Wait, what are you doing with that nitrous oxoide? Should I start worrying?

DonHopkins on July 29, 2016 | parent [–]

Reflecting on the S-expressions I just typed!

qwertyuiop924 on July 29, 2016 | root | parent [–]

Well, when you're done with the nitrous oxide, just toss whatever you wrote into the obfuscated code contest.

DonHopkins on July 29, 2016 | root | parent [–]

There's a reason the paren keys had really fast auto-repeat!

Edit by way of reply since the edit window is closed:

I apparently have seen pics of what I thought was the symbolics space cadet but apparently it's some other keyboard with parens on 0 and 9.

My bad.

The MIT Lisp Machine keyboard and also the Symbolics keyboard(s) had parentheses on shift-9 and shift-0. They also had unshifted parentheses a row below, right next to the P.

Interesting, on AZERTY (french) keyboards, parentheses are unshifted. They are on 5 and on ° (the key just right of 0). On the other hand, { is on alt gr on 4, [ on alt gr on 5, ] on alt gr ° and } on alt gr + (right of °). I wonder if it influences the programming languages that people prefer, even just a bit. Or maybe the style? Unshifted parenthesis makes function call easier for example.

I know it sounds silly, but one of the things that I particularly like about Lisp is the lack of the shift key. Notably, you can use identifiers-like-this. Yea, I haven't made the plunge to move () off the shift key, but I barely notice it compared to having to alwaysTypeLikeThis or type_like_this.

The keyboard fatigue adds up, and it's just an intangible I like about the language.

nuh uh. They were where square brackets [ and ] are on a "normal" keyboard. See image here: https://twitter.com/qrs/status/863959923339792384